The UNITE/MORI 2004 survey of student experiences estimated that university students in the UK paid on average 54 per week in accommodation costs. Assume that this average is based on a sample of 755 students and that the population standard deviation for weekly accommodation costs is 11. (a) Construct a 90% confidence interval estimate of the population mean. (b) Construct a 95% confidence interval for the population mean. (c) Discuss what happens to the width of the confidence interval as the confidence level is increased. Does this result seem reasonable? Explain.